Ballesteros missed all of last year with a series of back injuries. He said he had been training hard and reached the point where he was making progress until discovering problems with the cartilage in his right knee.
'To my regret, this ailment has made me give up participating in this forthcoming Masters,' he said.
This is the 25th anniversary of Ballesteros' first victory in the Masters. He dominated Augusta National that year, building a 10-shot lead during the final round until giving away strokes on the back nine and winning by four. At age 23, he was the youngest Masters champion until Tiger Woods won in 1997 at 21.
Ballesteros also won the Masters in 1983, and he has three British Open titles. He has not made the cut at Augusta National since 1993, when he finished 43rd.
Ballesteros said he hopes to return at the Spanish Open, to be played the week after the Masters at San Roque Club. He also intends to play the British Open at St. Andrews in July.
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